Electric drive machines generally include an engine and a generator configured to provide electric power to an electric motor for driving the machine. On large work machines, such as dozers, tractors, and trucks, the electric motors are large and powerful, and the engines are required to provide a substantial amount of power to drive the electric motors. Because of this, the engines are also large and powerful. Starting these engines requires high levels of power.
One typical starting system for these engines includes a starter and a battery. The starter for these engines must be large and robust to turn the engine until it is operating. These starters may be expensive and may be prone to mechanical problems requiring maintenance and expense to keep them operating.
Because the energy required to start these large engines is often higher than the energy offered in a standard battery, some starting systems include a separate power booster to boost the battery power to a level sufficient to start the engine. These power boosters, like the starters, may be expensive and high maintenance.
Another typical starting system includes components that provide energy to the generator attached to the engine to turn the generator until the engine starts. One example of such a system is disclosed in U.S. Pat. No. 5,705,859 to Karg et al. The '859 patent discloses a system for starting an engine that uses a generator to crank the engine until it starts. Voltage is provided to the generator through an intermediate circuit that receives voltage from a battery that is boosted by a transformer. However, the system of the '859 patent still requires extra components to boost the battery power to a level sufficient to start the engine. For example, it requires a rectifier, an intermediate circuit, and a transformer between the battery and the generator.
The present disclosure is directed to overcoming one or more other deficiencies in the prior art. In particular, the present disclosure provides a method and system that reduces the number of components required to start an engine on an electric drive machine.